Apparatus for folding and stacking flexible material



Oct. 15, 1968 s. P. DAME 3,405,932

APPARATUS FOR FOLDING AND STACKING FLEXIBLE MATERIAL Filed Aug. 5, 19665 Sheets-Sheet 1 INVENTOR. STANLEY P. DAME ATTORNEYS Oct. 15, 1968 S. P.DAME 3,405,932

APPARATUS FOR FOLDING AND STACKING FLEXIBLE MATERIAL Filed Aug. 5, 19665 Sheets-Sheet 2 FIG.2

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APPARATUS FOR FOLDING AND STACKING FLEXIBLE MATERIAL Oct. 15, 1968 5Sheets-Sheet 3 Filed Aug. 5, 1966 F I G. 3 INVENTOR.

STANLEY P. DAME ATTORNEYS Oct. 15, 1968 S. P. DAME APPARATUS FOR FOLDINGAND STACKING FLEXIBLE MATERIAL Filed Aug. 5, 1966 5 Sheets-Sheet 4 FIG.4

INVENTOR.

STANLEY P. DAME WW, amwa;

ATTORNEYS Oct; 15, 1968 s. P. DAME 3,405,932

APPARATUS FOR FOLDING AND STACKING FLEXIBLE MATERIAL Filed Aug. 5, 19665 Sheets-Sheet 5 INVENTOR. STANLEY P. DAME WM, Olazufir 0d;

ATTORNEYS United States Patent 3,405,932 APPARATUS FOR FOLDING ANDSTACKING FLEXIBLE MATERIAL Stanley P. Dame, Somersworth, N.H., assignor,by mesne assignments, to Thompson Manufacturing Company, Inc.,Somersworth, N.H., a corporation of Massachusetts Filed Aug. 5, 1966,Ser. No. 570,642 8 Claims. (Cl. 270-68) ABSTRACT OF THE DISCLOSUREFlexible materials such as leather hides are folded and stacked by meansof an endless conveyor which delivers the material onto a horizontallyreciprocating table. The table moves in under the conveyor to pickup thefirst half of the material and then moves in an opposite direction topick up the remaining half which folds down over the first half. Thetable carries the folded material into a clamp which grabs the foldedend of the article and the table then reciprocates away from the clampwhich then releases the folded material onto a stack of previouslyfolded materials.

This invention relates generally to material handling and moreparticularly is directed towards a novel method and associated apparatusfor folding and stacking flexible material such as large sections ofleather hides or the like.

In certain material handling applications there is a need to fold andthen to stack pieces of flexible material. By way of example, in theleather industry hides undergo a splittin process and then are folded inhalf before being transferred to a subsequent operation. Since thesehides are usually of irregular outline, long, wide and heavy, they arequite difiicult to handle manually. It is therefore a rather arduousmanual operation to fold each hide as it comes from the splittingmachine and then stack it on a pallet. This is particularly true if thehide is in a slippery condition.

Accordingly, it is an object of the present invention to provide a novelmethod and associated apparatus for folding and stacking flexiblematerials.

Another object of this invention is to provide poweroperated apparatusfor automatically folding and stacking large flexible sheet form itemssuch as animal hides and the like.

Still a further object of this invention is to provide a folding andstacking apparatus for flexible sheet items which is capable of handlingitems in a variety of sizes and shapes.

More particularly, this invention features the method of folding andstacking flexible sheet form articles comprising the consecutive stepsof advancing the whole article edgewise in one direction through ahorizontal plane, dropping the leading edge of the article below theplane, then moving the leading edge of the article in a directionopposite to that of the remainder of the article and in a plane belowthe plane of the article and at the same speed, then reversing thedirection of the leading portion of the article when the leading edge issubstantially even with the trailing edge thereof, then moving the bothportions of the article in the same direction at substantially the samespeed and then finally dropping the now folded article.

This invention also features an apparatus for folding and stackingflexible sheet articles, comprising a first conveyor for advancing thearticle edgewise in one plane and in one direction at a certain speed, asecond conveyor adapted to reciprocate in a plane below the plane of thefirst conveyor but parallel thereto. The two conveyors are timed so thatthe leading edge of the article is fed onto the second conveyor so thatthe leading half is carried under the first conveyor in a directionopposite the movement of the trailing half of the article. When the twoedges are substantially even, the second conveyor is reciprocated in theopposite direction and at substantially the same speed as the firstconveyor whereby the article is delivered in a folded condition onto thesecond conveyor. At the end of the stroke of the second conveyor, thereis located a gripping mechanism for grabbing the creased end of thearticle whereby, as the second conveyor is again reciprocated to moveout from under the article, it will then be released by the grippingmechanism thus droppin the folded article onto a pile locatedtherebelow.

However, these and other features of the invention, along with furtherobjects and advantages thereof, will become more fully apparent from thefollowing description of a preferred embodiment of the invention withreference being made to the accompanying drawings, in which:

FIG. 1 is a view in perspective of a folding and stacking apparatus madeaccording to the invention,

FIG. 2 is a view in side elevation partly in section of the apparatus,

FIG. 3 is a top plan view thereof,

FIG. 4 is a sectional side elevation of the conveyor drive mechanism,and

FIG. 5 is a detailed sectional view in side elevation of the grippingand dumping mechanism.

Referring now to the drawings, the folding and stacking apparatus isgenerally organized about an open rectangular frame it mounted in ahorizontal plane by means of upright legs 12. The frame and legs form atable-like structure having a forward overhang 14 which supports anendless conveyor belt 16 between a pair of side rails 18 and 29. Theleading edge of the overhang 14 carries a lateral nose piece 22 which ispositioned at the discharge of a hide splitting apparatus (not shown).It will be understood that when a hide is fed into the splittingmachine, it is cut edgewise from end to end with the split or bottomportion being discharged below the overhang 14 to be carried away by aconveyor, for example, while the top portion of the hide, usually knownas the side indicated by the reference character 24, is carried onto theconveyor belt 16 in the direction indicated by the arrow 26.

By Way of a general description of the operation of the apparatus, theside 24 is carried rearwardly along the conveyor 16 and is transferredto a horizontally movable carriage 28 mounted rearwardly and below theconveyor 16. The carriage is arranged to be reciprocated from a.position underneath the conveyor 16 to a position over a stack 3G offolded sides 24 piled on a pallet carried by an elevator 32. Thecarriage 28 is timed so that a left-hand stroke, as viewed in FIGS. 1and 2, will start the leading edge of the carriage under the conveyor 16at substantially the same time that the leading edge of the side 24 isbeing discharged downwardly and to the right from the conveyor 16. Thecarriage 28 will continue moving to the left as the side is fed onto thecarriage until the leading end of the side is substantially even withthe trailing end of the side still on the conveyor 16. At this point thecarria-ge 28 will retract towards the right at substantially the samespeed as the conveyor 16. This retraction of the carria ge will carrythe side to the right with the upper and trailing half of the sidecoming down on top of the lower leading half of the side to thereby foldthe side in half.

The folded side is carried to the extreme right by the carriage andagainst a clamping mechanism indicated generally by the referencecharacter 34. This clamping mechanism will grab the folded end of theside and hold it as the carriage 28 again reciprooates to the left,moving out from under the folded side. When the carriage has moved fullyout from under the side, the gripping mechanism will pivot and releasethe side 'down onto the stack 30. A tamping mechanism 35 associated withthe gripping mechanism will push down against the folded edge of theside to keep the top of stack of hides level. The elevator 32 is timedwith the driving mechanism to drop in predetermined increments for eachcycle so that the top level of the stack is maintained at substantiallythe same height.

A detailed description of the construction of the various portions ofthe apparatus will now be given.

Starting with the conveyor belt 16, the entire conveyor assembly, whichis carried by the side rails 18 and 20, is mounted to the frame so as topermit the conveyor assembly to be displaced to the right as viewed inFIGS. 1 and 2. It should be noted that sliding capability is notutilized during operation of the machine but is provided only tofacilitate access to the discharge end of the slitting machine which isnormally mounted in close relation to the stacker and requires frequentservicing. In any event, the conveyor system comprises the belt 16 and aseries of rollers 36, 38, 4t 44 and 46 over which the belt 16 is roven.The belt follows an inclined portion at its feed end with the upperreach being horizontal. The belt then moves downwardly over roll 40 andthen rearwardly under roll 42 where it is carried back and around roll44, again forwardly to roll 46, and then rearwardly to the leading roll36. The roll 46 is the driving roll and roll 44 is the tension rollwhich maintains a constant tension on the belt by means of powercylinders 50 engaging each end thereof. In practice, the power cylinders50 are actuated edge guiding devices, well known in the art, whichrespond to the position of the edge of the moving conveyor. With thisarrangement the cylinders 50 will respond to maintain an even tension onthe belt and also will cause the belt to track through a substantiallystraight path.

The side 24 is fed over the nose 22 and carried up the inclined portionof the belt, along the fiat upper reach and is then delivered downwardlyonto the carriage. In order to guide the side downwardly a funnel orbafiie 52 is mounted over the discharge end of the conveyor 16. Spacedacross the discharge end of the conveyor is a series of trips or firsttiming means 54 in the form of elongated fingers which extend into closerelation to the belt. The fingers are actuated by the presence of a sideon the conveyor and it will be understood that as the side is guideddownwardly through the funnel, the leading edge of the side will strikethe trip fingers and the fingers in turn will actuate an associatedswitching mechanism to simultaneously pivot the finger counterclockwiseand out of the way of the side and start the carriage 28 reciprocatingto the left as viewed in FIG. 2. In practice, the switches for thedetecting fingers 54 are connected in parallel pairs so that at leasttwo switches will have to be closed before the machine is cycled.Otherwise, small bits of leather, for example, may strike one 'of thefingers to start a cycle when no hide is present or when the hide is inan incorrect position.

The several trips are moved out of position by means of a power cylinder56 drivingly connected to a rocker arm 58 keyed to a horizontal rod 60supporting the several trips.

When the trips 54 are actuated, they commence a cycling operation of thecarriage 2-8. The carriage 28 which at the start of the cycle is in aright hand position as viewed in the FIG. 1, will start moving to theleft at substantially the same speed as the conveyor belt 16, the upperreach of which will be moving to the right. The carriage 28 rides onparallel tracks 62 mounted oppositely one another on the inner sides ofthe frame 10. These tracks extend in under the conveyor belt assemblyand engage rollers 64 mounted to the carriage. The carriage is alsoprovided with an elongated rack 66 along either side thereof which rackmeshes with a :gear 68 driven by a motor 70 through a chain drive 72. Itwill be understood that the motor 70 is reversible in order toreciprocate the carriage back and forth as-required. Otherreversibledriving arrangements may be provided to actuate the carriage.

In any event, the operation of the carriage is timed to coincide withthe side 24 as it is discharged down from the conveyor 16 as it movespast the roller 42. The carriage 28 as it starts moving to the left asin FIG. 4 picks up the leading edge of the side coming otfthe conveyor16. The carriage starts to move in under the lower reach of the conveyor16 carrying with it the leading portion of the side. In this fashion theleading or lower portion of the side is carried in a direction'oppositeto the trailing upper portion still on the conveyor 16. The carriagecontinues to move until it reaches the end'of its left hand stroke. Atthe end of its stroke it will trip a limiting switch causing the motorto reverse the direction of rotation of the gear 68 thereby starting thecarriage on a return stroke to the right. The stroke of the carriage issuch that it will star-t its return stroke to the right whenapproximately one half of the side has been deposited on the carriagewith the other half still remaining on the conveyor. In this conditionthe side should come out folded substantially in half. In any event, asthe carriage starts moving to the right on its return stroke atsubstantially the same speed as the conveyor 16 or slightly in excessthereof, the trailing upper half of the side will continue to be feddown onto the carriage only it will now come down on top of the leadinglower half of the side already on the carriage and in this manner theside is folded in half.

The now folded side is carried away from the conveyor 16 to the righttowards the gripping mechanism 34. The gripping mechanism may beselectively positioned lengthwise of the frame by manipulation of a pairof lead screws mounted on the insides of the frame 10 and engagingfollowers 82 supporting the gripping mechanism. The lead screws areoperated by means of a hand crank 84 located at one corner of the frameand connected to the lead screws by means of an extension rod 86 andbevel gears 88.

The carriage is moved to the right towards the gripping mechanism untilit reaches the end of its stroke determined by the position of thegripping mechanism, where it trips another limiting switch or secondtiming means to again reverse the motor 70 and reciprocate the table 28to the left back towards the conveyor.

The gripping mechanism 34 includes an elongated scoop 90 mounted to arotatable support 92. The support 92 is drivingly connected by a rockerarm 94 to a power cylinder 96. Actuation of the cylinder 96 will causethe arm 94 and the scoop 90 to rotate counterclockwise as viewed in FIG.5 for reasons that will presently appear. Concen trically rotatableabout the support 92 is another pair of rocker arms 98 which carry a bar100. The rocker arms 98 are drivingly connected to power cylinders 102and by actuation of the cylinders 102 the rocker arms 98 will bias thebar counterclockwise down against the scoop 90. It will be understoodthat the bar 100 is timed to come down against the scoop when the foldedend of the side 24 has been carried up into the scoop as suggested indotted line in FIG. 5. The bar will come down and grip against thefolded end of the side and pinch it against the scoop. Once this hasbeen accomplished, the carriage 28 will start its stroke to the left asviewed in FIG. 5 and move out from under the folded side which is heldby the scoop and bar. The side will drape down onto the stack 30 andonce the carriage is moved fully out from under the side the cylinder 96will. be actuated to bias the scoop 90 counterclockwise dropping thefolded edge down onto the stack. Once the side is fully released, thecylinder 96 again actuates to bias the scoop back into position to pickup the next side.

Also shown in FIG. 5 is a braking cylinder 104 which serves to bring thecarriage 24 to a controlled stop at the end of its stroke.

In order to protect against damage to the scoop or carriage in the eventthat the side 24 should accidentally get caught between the scoop andthe carriage, the leading end of the carriage, indicated at 106, may bein the form of the spring loaded hinge whereby that portion of thecarriage will pivot down in the event that a side should jam between thescoop and the carriage.

Once the side is fully released and laid onto the stack the tampingmechanism 35 is automatically actuated so as to press the folded end ofthe side down fiat against the stack so as to form a smooth even pile ofsides. This tamping mechanism comprises a pair of power cylinders 108which carry a tamping plate 110 positioned over the edge of the stack.Actuation of the cylinders 108 will reciprocate the plates 110downwardly to push against the top of the stack of sides under pressureand flatten out the top of the stack. In order to insure that the platemoves smoothly under the action of the two cylinders a pair of verticalracks 112 is provided, one rack being associated with each cylinder 108.The lower end of each rack is connected to the plate 110 and moves upand down with the plate. The rack rides in suitable bearings and eachrack meshes with a pinion 114. The pinions are keyed to a common crossshaft 116 whereby operation of one rack and cylinder will follow theoperation of the other rack and cylinder for smooth operation of thereciprocated plate.

The elevator 32 on which the sides are stacked is essentially a platformprovided with threaded followers 118 at each corner thereof engagingvertical lead screws 120. The lead screws 120 are actuated in unison toturn a predetermined amount upon each operating cycle of the apparatus.Each time the lead screws are actuated, the elevator 32 drops for adistance substantially corresponding with the thickness of a folded sidedeposited thereon. In this fashion the top level of the stack of sidesremains substantially constant. When the elevator reaches the bottommost position, the pile of sides is removed and the elevator returned toa starting position. A motor 122 is drivingly connected to the leadscrews 120 and is actuated by suitable switches so as to move theelevator in proper timed sequence.

While the invention has been described with particular reference to theillustrated embodiment, it will be understood that numerousmodifications thereto will appear to those skilled in the art.Accordingly, the above description and accompanying drawings should betaken as illustrative of the invention and not in a limiting sense.

Having thus described the invention, what I claim and desire to obtainby Letters Patent of the United States is:

1. Apparatus for folding and stacking a flexible sheet article,comprising:

(a) a first conveyor adapted to carry said article in a fiat opencondition in one direction through a first horizontal plane,

(b) a second conveyor mounted in a second horizontal plane below saidfirst plane for reciprocation in said one direction and in an oppositedirection,

() means for feeding the leading end of said article from said firstconveyor to said second conveyor,

((1) first timing means for moving said second conveyor in said oppositedirection to receive the leading end of said article and carry it insaid opposite direction until the leading end is abreast the trailingend on the first conveyor and then reversing the second conveyor to movein said one direction whereby said trailing end will fold down on saidleading end, and

(e) a clamp located adjacent said second conveyor when said secondconveyor has reached the extent of its travel in said one directionwhereby said article may be held by said clamp as said second conveyorreciprocates in said other direction moving out from under the foldedarticle.

2. Apparatus according to claim 1 including a tamping mechanism having aplate mounted for vertical reciprocation and power means drivinglyconnected to said plate and timed to move said plate against saidarticle after said article is released by said clamp.

3. Apparatus according to claim 1 including an elevator mounted belowsaid second conveyor in position to receive articles released by saidclamp and adapted to support said stack of articles.

4. Apparatus according to claim 3 including elevator control meansdrivingly connected to said elevator for lowering said elevator inpredetermined increments each cycle of operation of said conveyors.

5. Apparatus according to claim 1 including a lead screw and followeroperatively connected to said clamp for selectively positioning saidclamp with respect to said second conveyor.

6. Apparatus according to claim 1 wherein said first timing meansincludes an array of article sensing devices arrayed across thedischarge end of said first conveyor and adapted to respond to thepresence of an article on said first conveyor.

7. Apparatus according to claim 1 wherein said clamp includes a scoopextending across the path of said article in said second plane to pickup the folded end of said article as it is carried in said one directionand a bar coextensive with said scoop mounted for pivotal movement downagainst said scoop to clamp the folded end of said article and means forpivoting said scoop downwardly to release said article.

8. Apparatus for folding and stacking a flexible sheet article,comprising:

(a) a first conveyor adapted to carry said article in a flat opencondition in one direction through a first generally horizontal plane,

(b) a conveyor table mounted in a second generally horizontal planebelow said first plane for reciprocation in said one direction and in anopposite direction,

(c) means for feeding the leading end of said article from said firstconveyor to said conveyor table,

(d) first timing means for moving said conveyor table in said oppositedirection to receive the leading end of said article and carry it insaid opposite direction until the leading end is abreast the trailingend on the first conveyor and then reversing the conveyor table to movein said one direction whereby said trailing end will fold down on saidleading end, and,

(e) a clamp located in a position adjacent said conveyor table when saidconveyor table has reached the extent of its travel in said onedirection,

(f) said clamp being adapted to engage said article whereby said articlemay be held by said clamp when said conveyor table is withdrawn in saidother direction.

References Cited UNITED STATES PATENTS 1,270,334 6/1918 Schumacher 27l84 2,015,550 9/1935 Elberty 270-68 2,549,202 4/1951 Idelman 271883,003,760 10/1961 Scheu et a1 27082 EUGENE R. CAPOZIO, Primary Examiner.

P. V. WILLIAMS, Assistant Examiner.

